1. Field of the Invention
This invention relates to hand held optical scanners for use in manual scanning printed text, independent of font type, and more particularly, to hand held optical scanners for use with a character recognizing and voice synthesizing reading machine to enable manual scanning by the blind or by the print handicapped for the purpose of converting substantially any printed text into synthesized human voice.
2. Description of the Prior Art
In order for a blind or visually impaired person to obtain the benefit of written or non-oral information, whether it be for education, entertainment, or an employer, the information must be in braille or orally presented either by a person or by a recording of an oral rendition. There is a tremendous cost advantage for schools, libraries and employers, if regular books, magazines, and other printed material could be used by the sight impaired, for the cost to reproduce them in braille or recorded sound is avoided, as well as the added cost for the extra storage space that would be required.
An existing reading machine for the blind requires that the visually impaired person take the printed material, such as a book, to the reading machine and place it opened face down on a fixed platen, one page at a time, so that the printed text thereon may be scanned, converted into video or digitized data, converted askew representation, and then converted to sound by a voice synthesizing system.
There are disadvantages of using a console type reading machine for the blind. It is centrally located requiring the printed material be brought to it and such reading machine takes up space whether in use or not. Also, the user must lift a bound volume of printed material after each page has been scanned, the page must be turned, and the next page in the bound volume realigned on the platen. Such manipulation of bound volumes of printed material is cumbersome for a visually impaired person, and the task of scanning the pages would be simpler if the bound volume could remain stationary and only the pages turned after they were scanned by small, compact hand held scanner.
Accordingly, this invention provides a small hand held scanner connected by flexible cable to a portable character recognizer and voice synthesizer, which may be conveniently stored when not in use, and taken to the particular location in the building that is closer to the usual location of the printed material to be used by the visually impaired person. Because the portable voice synthesizer is compact and does not require a relatively large fixed platen, it may be conveniently moved to temporary locations, such as, for example, hospitals and nursing homes. Further, these devices may be used by the sighted individuals who are print handicapped; that is, used by the illiterate, uneducated, or non-English speaking people.
To eliminate the fixed platen and enable a portable reading machine, a hand held scanner is required that is the subject of this invention. There are many hand held scanners known in the industry for producing hard copies of the scanned portions of the printed materials, for reading bar code symbols, and the like, but none are adapted for high image quality character recognition that is required for multi-font scanning in connection with a reading machine for the blind.
U.S. Pat. No. 3,541,248 to Young discloses a recording system which employs a hand held scanner and a recorder. A spot of light is moved across both the material to be copied by the scanner and a light sensitive medium by the recorder, with the scanning of the spots both being correlated to the movement of the scanner across the material to be recorded. This correlation is achieved by a light chopper or similar device which generates signals indicative of the rate of travel of the scanner across the material being scanned. Thus, the recording or reproduction of the image scanned is independent of the speed at which the scanner is moved across the original image.
U.S. Pat. No. 4,553,035 to Malinsky et al discloses a data acquisition control system for a hand held, manually moved reader comprising an optical character recognition system (OCR) having a head for scanning characters and an adjacent head for monitoring the position of points of a reticle normal to a rail contained on a manually positioned base. The reticle is disposed on the base adjacent the rail. When the base is positioned adjacent a row of characters to be scanned, the heads are guided by the rail as they are manually moved, one head scans the characters and the other scans the reticle. Every time the head moves a predetermined distance, it is caused to output data relating to the series of characters scanned.
U.S. Pat. No. 4,574,317 to Scheible discloses a hand scannable portable copier and method comprising a solid state optical scanner array and a thermal printhead array in a pocket-sized housing. The scanning is done either with the help of a constant speed motor or manually. The system is also provided with a separate guide element to assist the user in scanning the original document in straight lines.
U.S. Pat. No. 4,523,235 to Rajchman discloses an electronic microcomputer apparatus using an electronic pen which scans a line of text manually and stores signals from optical sensors in a reading head of an electronic memory. A line of photosensors within the pen is oriented vertically so that each of the sensors sweep a horizontal line. A pair of positioning wheels, one for a writing end of the pen and one for a reading end of the pen, are used to insure correct relative positioning of the characters. The manual sweep can proceed at any speed, since the horizontal location of the sensors is monitored by positioning wheels. One wheel guides the pen and has angular space marks which are optically detected to activate the counter which in turn addresses the memory.
U.S. Pat. No. 4,544,842 to Engemann et al discloses an arrangement of light conductors that are correlated with the sensor areas of an array of image sensors. The light conductors consist of glass wafers or fibers whose respective width or diameter corresponds to the width of a sensor area. The light conductors are joined to form a block having a top surface area which corresponds to the document to be scanned line by line by joint movement of a light source and the image sensor array.
U.S. Pat. No. 4,538,060 to Sakai et al discloses a hand held bar code reader having a reading sensor for converting optically readable information into an electrical signal by electronically scanning an image of optical information, such as a bar code. A detector is provided to detect the intensity of light incident on the information label on which the information is provided. Data indicative of the light intensity is used to determine a subsequent scanning period in such a manner that the scanning period of the reading sensor is shortened when the light intensity increases or vice versa. Since the decrease in the scanning period results in lower output voltage from the reading sensor, undesirable saturation in circuitry following the reading sensor is effectively prevented.
An article entitled "Hand Operated Scanner" by J. C. Tandon, Xerox Disclosure Journal, Vol. 9, No. 2, March/April, 1984, discloses a hand operated scanner comprising a manually movable head and a guide rail along which one end of the head may be moved. The portion of the head extending beyond the guide rail contains a gradient index fiber lens and sensor array for scanning documents. When used, the scanner is placed on the document to be scanned so that the sensor array may scan the desired part of the document to be read thereby as the head is manually moved along the guide rail.
U.S. Pat. No. 4,375,916 to Levine discloses a portable, detachable image reader and memory for use with a photocopy machine to read and temporarily store video images of documents to be copied. A visual display incorporated in the portable reader enables the user to check the legibility and reproducability of the document scanned so that the user may erase an improper or incomplete image and make another while the document to be copied is still available to the portable reader. In addition, means for sampling different spatial portions of the video image generated by the portable reader which is less than the image scanned, indicates an estimate of the reproducability of the video image produced by the image reader.
U.S. Pat. No. 3,245,158 to Schwartz discloses a hand held scanner for the blind having a rotatably adjustable variable slot which may be sonically adjusted about a fixed partition within the scanner, so that light from a light source in the scanner and directed to the document to be read is reflected into the variable slot. The slot is manually positioned in accordance with tones produced by photosensors on each side of the partition to match the height of the printed characters to be scanned. This is accomplished when the variable slot is adjusted so that the partition is exactly equidistant of the top and bottom of the characters to be scanned.
U.S. Pat. No. 4,575,625 to Knowles discloses a portable hand held laser scanner system located within a compact housing. The laser is operative when triggered by the user to produce a laser beam which exits the housing to scan a target such as a bar code symbol located adjacent thereto and to receive light reflected from the target. A computer in the housing is arranged for decoding the reflected signal. The computer is arranged to control and override the operation of the laser when the amount of laser light produced within a predetermined period time reaches a threshold value that would be unsafe for the user.
U.S. Pat. No. 3,318,996 to Garfield et al discloses a hand held scanner connected to a reproducing machine. The scanner has a synchronizing roll mounted on one side thereof which frictionally engages the document to be copied and reproduced. The roll controls a relay whose contacts control a stepping motor. The stepping motor provides the power to drive rolls which move paper through the reproducing machine in synchronism with the speed of the manual movement of the scanner.
U.S. Pat. No. 3,346,692 to Garfield et al discloses a hand held scanner and reproducing machine having circuitry to assure movement of the recording material through the reproducing machine is in proportion to the movement of the reading head prior to recording and to prevent recording unless it is moved in synchronism with the scanning head.
U.S. Pat. No. 3,512,129 to Garfield discloses a hand held scanning device for selectively reading, character recognition apparatus connected to the scanning device, and character reproducing machine such as a typewriter connected to receive the output signal from the character recognition apparatus and reproduce the same in printed form. In addition to having the scanned material retyped by the typewriter, this combination can be used to edit and verify the accuracy of the reproduced copy.